From: "Gwara, Mateusz" <mateusz.gwara@secunet.com>
To: "rui.zhang@intel.com" <rui.zhang@intel.com>
Cc: "163ff391dc6d4f828ecff95e87f5003d@secunet.com"
<163ff391dc6d4f828ecff95e87f5003d@secunet.com>,
"daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>,
"Wassenberg, Dennis" <Dennis.Wassenberg@secunet.com>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"lukasz.luba@arm.com" <lukasz.luba@arm.com>,
"Gwara, Mateusz" <mateusz.gwara@secunet.com>,
"rafael@kernel.org" <rafael@kernel.org>,
"ricardo.neri@intel.com" <ricardo.neri@intel.com>,
"srinivas.pandruvada@intel.com" <srinivas.pandruvada@intel.com>
Subject: Re: TCC cooling on Meteorlake
Date: Mon, 17 Mar 2025 10:31:31 +0000 [thread overview]
Message-ID: <24742814b1fc433cb778dc6ecb7c671d@secunet.com> (raw)
> what do you see from
> /sys/bus/pci/devices/0000:00:04.0/tcc_offset_degree_celsius?
>It should return 0 if noone changes the offset.
The offset is set to 14°C on a Meteor Lake CPU.
This behavior applies to our custom kernel(based on vanilla 6.8) as well as the regular Ubuntu kernel builds (tested with 6.8 and 6.14)
> tcc offset is an offset to tjmax, no matter what the tjmax value is,
> right?
That's true.
We run our Raptor Lake devices with a TCC Offset of 3°C which is what is usually set for those and generations before on a regular Ubuntu for example.
This means we actively make sure this value is set to 3 as 0 would mean being too close to tjmax and risking an uncontrolled shutdown(i.e. actually reaching tjmax).
Having this value so close to tjmax allows to prevent premature thermal throttling.
So, the much higher default value for Meteor Lake TCC offset basically cancels out their higher temperature range.
> yeah. We should add this. Patch will be submitted soon.
Thanks in advance!
Mateusz
next reply other threads:[~2025-03-17 10:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-17 10:31 Gwara, Mateusz [this message]
2025-03-24 0:17 ` TCC cooling on Meteorlake Zhang, Rui
-- strict thread matches above, loose matches on Subject: below --
2025-03-26 17:46 Gwara, Mateusz
2025-03-11 12:19 Gwara, Mateusz
2025-03-13 5:29 ` Zhang, Rui
[not found] <f733005155e64d489ae18d7d357bada9@secunet.com>
2025-02-24 11:27 ` Gwara, Mateusz
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